Describe the bug
For a Flutter app that integrates Firebase, the iOS build now pulls the Swift Package version of flutterfire, which is then entire repo that also includes all the Dart packages. The expectancy is that Dart should not analyze anything inside that directory (by Dart/Flutter convention, or indicated by .gitignore), but it did and poured about 13K+ errors per copy of flutterfire.

To Reproduce
Steps to reproduce the behavior:

1. Create a Flutter app with iOS support
2. Integrate Firebase (or simply include any Firebase Flutter package as a dependency in app package's pubspec.yaml)
3. Do an iOS build to let Flutter pull the flutterfire repo as a Swift package
4. Restart VS Code, wait for a while and see thousands of errors

Expected behavior
Anything in build directory should be ignored.

Screenshots
N/A

Please complete the following information:

• Operating System and version: macOS 26.3
• VS Code version: macOS 1.113.0
• Dart extension version: 3.130.1
• Dart/Flutter SDK version: 3.13.0-79.0.dev / 3.45.0-0.1.pre
• Target device (if the issue relates to Flutter debugging): N/A